A pharmaceutical production batch size is defined in accordance with the CFR21 (Code of Federal Register) as a homogenous mixture of ingredients. A “batch” or “lot” as defined in the WHO GMP guideline (TRS 908 Annex 4) as “a defined quantity of starting material, packaging material, or product processed in a single process or series of processes so that it is expected to be homogeneous.
It may sometimes be necessary to divide a batch into a number of sub-batches, which are later brought together to form a final homogeneous batch. In the case of terminal sterilization, the batch size is determined by the capacity of the autoclave. In continuous manufacture, the batch must correspond to a defined fraction of the production, characterized by its intended homogeneity. The batch size can be defined either as a fixed quantity or as the amount produced in a fixed time interval”.
In those instances where smaller sub-batches are manufactured and pooled together, it requires combining them in a larger container wherein the sub-batches can be mixed to a homogenous mixture. However, in many situations, a larger container use can be prohibitive such as in clean rooms and thus there is an unmet need to invent systems that will allow mixing between containers without the need to mix the entire content in a larger container.
The idea of mixing contents of multiple containers also offers many significant financial and regulatory advantages.
The science of pharmaceutical manufacturing teaches us that changing the size of a batch is not a simply exercise. As the size of a batch changes, the dynamics of mixing also changes along with the dynamics of any reactions taking place in the manufacturing process and as a result a manufacturer is required to conduct studies to validate the conditions of manufacturing to assure that a specific size of a batch would consistently result in the same product. Therefore manufacturers are required to invest substantial time and money in validating different batch sizes to meet their need for specific quantities of the product.
Biological manufacturing of drugs using bioreactors even faces greater challenges as changes in the volume of liquid (nutrient media and biological culture) in the bioreactor container significantly changes the conditions required to produce a product consistently. The factors that are of significant importance include the geometry of the container, the amount of gasification, the amount and the nature of agitation of the liquid and as a result it is not possible to predict the behavior of manufacturing process unless it is practiced and appropriate corrections made to various parameters of the manufacturing process.
Since the manufacturers of drugs are often faced with a choice of making a larger or a smaller batch at a time, the most obvious exercise conducted is to validate several batch sizes and use a specific batch size based on the current need of manufacturing. The use of different batch sizes also require making available different size of vessels, and other technical attachments to a bioreactor, making the cost of maintaining several validated batch sizes very high. However, as biological products are most expensive to manufacture and often have a shorter shelf-life, it is inevitable for the manufacturers not to maintain several validated batch sizes.
Since bioreactors mainly employ liquid contents, they are easier to mix and finding a solution to mix the contents of several bioreactors in a manner that it would meet the requirement of the FDA in accordance with CFR21 for a single batch would reduce the cost of manufacturing significantly by reducing the number of batches that need to be validated and affording the flexibility to manufacturers to produce different sizes of batches at will using fewer variations in the manufacturing equipment.
There is no prior art that teaches on combining the contents of several bioreactors in such manner as to constitute a single batch. The instant invention not only resolves this critical hurdle in reducing the cost of production but also teaches a commercial level applications where hundreds and thousands of liters of liquid can be processed using low-cost solution to mix liquids.